1. Field of the Invention
The present invention relates to vehicle seat suspension systems for garden tractors or the like, and more particularly relates to seat suspension systems providing independent adjustments for leg room and for the weight of operators of considerably different height and weight.
2. Description of Prior Art
Many different types of seat suspension systems have been used in the past for garden tractors or the like. However, applicant knows of no system that is independently adjustable for both leg room and for differences in operator's weights.
Applicant's assignee has used leaf springs in seat suspensions for garden tractors and riding mowers for many years. Although such suspension systems were inexpensive, forward adjustment of the seat to provide leg room adjustability was limited to less than about two inches, and no provision was made to alter the spring position under the seat for operator comfort. Many of assignee's vehicles used seat suspensions with transversely extending leaf springs; while others used pairs of transversely spaced, longitudinally extending, U-shaped leaf springs. It was determined that it is difficult to control the rate, shape, and heat treatment of leaf springs, and that the springs were very often too stiff and had poor lateral stability.
Other seat suspension systems are evidenced by the following patents.
U.S. Jackman Pat. No. 1,261,396 which issued on Apr. 2, 1918 is representative of the prior art and discloses a foldable seat which is supported for leg room adjustment on a pair of leaf springs having forwardly curved ends pivoted to a vehicle. In one embodiment, a coil spring is connected to the seat to aid in supporting the rider. However, the coil spring is not adjustable relative to the position of the seat for providing independent leg room and weight adjustment for the rider's comfort.
U.S. Dufaux Pat. No. 1,747,932 which issued on Feb. 18, 1930 discloses an embodiment of a seat that is pivoted at its forward end and is supported at its rear end by a coil spring that is longitudinally adjustable. However, the seat is not adjustable to vary the leg room of persons of different heights.
U.S. Pat. No. 2,530,041 which issued on Nov. 14, 1950 discloses a seat mounted on a long narrow downwardly bent bar that is pivotally connected at its lower end to a vehicle. Although the seat is resiliently supported by a coil spring, no provision is made for weight or leg room adjustment, and the narrow width of the bar would indicate poor lateral stability of the seat.
U.S. Hoffmeyer Pat. No. 3,826,530 dated July 30, 1974 discloses a seat mounted on a garden tractor that is adjustable forwardly and rearwardly for varying leg room. However, adjustments for comfortably accommodating operators of different weights is not provided.